Melt butter in a heavy skillet.,Add onion and cook over medium heat until tender.,______,Add 1/2 cup potato chips, egg, salt and salmon.,Mix well. Shape into six patties.,Coat with remaining potato chips.,Heat oil in skillet.,Add patties; fry on one side until golden brown. Turn and fry other side until golden brown.,Drain on paper towel. Serve on toasted hamburger buns.,Yield: 6 servings.